Exhaust structure of construction machine

Abstract

An upper surface part of an engine guard forming an engine room is formed by a bonnet for opening and closing a maintenance port and a fixed hood. On the lower surface side of the bonnet is disposed a movable duct in a state that when the bonnet is opened the movable duct is moved integrally with the bonnet so as to open the maintenance port. On the lower surface side of the fixed hood, is disposed a fixed duct in a state that when the bonnet is closed one end of the fixed duct is connected to one end of the movable duct in the air flow direction. An exhaust duct is formed by both the movable duct and the fixed duct.

1. An exhaust structure of a construction machine, comprising:
 an engine guard forming an engine room in which an engine, a heat exchanger and a cooling fan are installed, the engine guard having an exhaust port; 
 an exhaust duct for absorbing sound disposed in said engine room, the exhaust duct being constructed such that the air taken from the exterior into said engine room by said cooling fan passes around said heat exchanger and said engine and through said exhaust duct, and then is exhausted from said exhaust port to the exterior; 
 a bonnet for opening and closing a maintenance port, and a fixed hood, the bonnet and the fixed hood forming an upper surface part of said engine guard; 
 a movable duct disposed on the lower surface side of said bonnet, the movable duct being provided in a state that when said bonnet is opened, the movable duct is moved integrally with said bonnet so as to open said maintenance port; and 
 a fixed duct disposed on the lower surface side of said fixed hood, the fixed duct being provided in a state that when said bonnet is closed, one end of the fixed duct is serially connected to one end of said movable duct in the air flow direction, 
 wherein said exhaust duct is formed by said movable duct and said fixed duct. 
 
   
   
     2. The exhaust structure of the construction machine according to  claim 1 , wherein said bonnet is constructed openably by a hinge member, and by an opening and closing movement of said bonnet, one end of said movable duct is separated from and connected to one end of said fixed duct. 
   
   
     3. The exhaust structure of the construction machine according to  claim 1 , further comprising a movable duct receiving portion overlapping an end of said movable duct from the outside when said bonnet is closed, wherein said movable duct receiving portion includes bottom wall and side walls of one end of said fixed duct extended to the movable duct. 
   
   
     4. The exhaust structure of the construction machine according to  claim 1 , further comprising:
 a duct sealing material for sealing both said fixed duct and said movable duct, the duct sealing material being provided between a movable duct receiving portion of said fixed duct and an end of said movable duct overlapped by said movable duct receiving portion. 
 
   
   
     5. An exhaust structure of a construction machine, comprising:
 an engine guard forming an engine room in which an engine, a heat exchanger and a cooling fan are installed, the engine guard having an exhaust port; 
 an exhaust duct for absorbing sound disposed in said engine room, the exhaust duct being constructed such that the air taken from the exterior into said engine room by said cooling fan passes around said heat exchanger and said engine and through said exhaust duct, and then is exhausted from said exhaust port to the exterior; 
 a bonnet for opening and closing a maintenance port, and a fixed hood, the bonnet and the fixed hood forming an upper surface part of said engine guard; 
 a movable duct disposed on the lower surface side of said bonnet, the movable duct being provided in a state that when said bonnet is opened, the movable duct is moved integrally with said bonnet so as to open said maintenance port; and 
 a fixed duct disposed on the lower surface side of said fixed hood, the fixed duct being provided in a state that when said bonnet is closed, said fixed duct and movable duct are arranged substantially coaxially such that one end of the fixed duct is connected to one end of said movable duct in the air flow direction, 
 wherein said exhaust duct is formed by said movable duct and said fixed duct.